Controller for electric motors



No. 625,|5l. Patented May 16, I899.

H. P. DAVIS 81. G. WRIGHT. CONTROLLER FOR ELECTRIC MOTORS.

(Application filed Oct. 98, 1896. Renewed. Nov. 9, 1898.)

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$5 3M? fltM No. 625,!51. Patented May l6, I899. H. P. DAVIS &. G. WRIGHT.

CONTROLLER FOR ELECTRIC MOTURS.

(Application filed Oct. 28, 1896. Renewed Nov. 9, 1898.)

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H. P. DAVIS & a. wman'r.

CONTROLLER FOR ELECTRIC MOTORS.

(Application filed Oct. 98, 1896. Renewed Nov. 9, 1898.) (No Model.) 4 Sheats-Sheet 3.-

m: Noam PETERS co. wm'aunw, msmus TTTTT cv No. 625,!5l. Patented May I6, I899. H. P. DAVIS & G. WRIGHT.

CONTROLLER FOR E'LEGTRIC MOTORS.

(Application filed Oct. 28, 18198. Benewqd Nov. 9, 1898.\

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i I T 88 33 2.9 i 8 I I I 35 V 34 l 2 wwweooeo amveuto cs UNITED STATES PATENT OFFICE.

HARRY P. DAVIS, OF PITTSBURG, AND GILBERT WRIGHT, OF YVILKINSBURG, PENNSYLVANIA, ASSIGNORS TO THE WVESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, OF PITTSBURG, PENNSYLVANIA.

CONTROLLER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 625,151, dated May 16, 1899.

Application filed October 28, 1896. Renewed November 9,1898. Serial No. 695,989. (No model.)

To (tZZ whom it may concern.-

Be it known that we, HARRY P. DAVIS, re siding in the city of Pittsburg, and GILBERT \VRIGHT,residing in the town of WVilkinsburg, Allegheny county, Pennsylvania, citizens of the United States, have invented a new and useful Improvement in Controllers for Electric Motors, (Case N o. 717,) of which the following is a specification.

Our invention relates to controllers for electric motors, and has particular reference to devices of this character which are employed for controlling the power'and speed of electric-railway motors. v

The objects of our invention are, first, to provide means which will close the circuit independently and in advance of any changes in the circuit connections or variation in resistance by means of the controller-drum and the stationary contacts cooperatin g therewith, which will also automatically open the circuit prior to the change from series to parallel connection and prior to a reversal of the controller-drum and which will preclude the closing of the circuit by a forward movement of the controller-handle from any position except such as will insure the inclusion of. considerable current-reducing resistance, and, second, to provide means whereby the current may be so reduced at the terminals of the circuit making and breaking switch prior to breaking the circuit as to prevent theformation of arcs.

In the accompanying drawings, Figure 1 is a'view, partially in front elevation and partially in section, of the controller-stand and the operating parts, the cover being removed. Figs. 2 and 3 are sectional views taken, respectively, on lines acsoand 3 1 of Fig. 1. Figs. 4., 5, and 6 are views showing the switch-actuating cams and the cooperating rocking head in three of thepositions which they assume in practice. Fig. 7 is a section on line .2 ,2 of Fig. 1, looking upward. Figs. 8 and 9 are side and rear elevations, respectively, of the rocking head for operating the series switch. Fig. 10 is a detail View, partially in side elevation and partially in longitudinal section, of the controller-d rum, its shaft, and the cooperating notched plate and switch-acvswitch being utilized as a supporting-post tuating cams. Fig. 11 is a diagrammatic development of the controller-drum, the combined reversing and out-out switches, and circuits. Fig. 12 is a diagram showing the circuits throughthe motors and resistances in the various positions of the controller-drum.

Reference being now had to the details of construction illustrated in the drawings, 1 is the supporting frame or stand of the controller, and 2 is the controller-drum.

3 and 1 are the respective drums of a combined reversing and cut-out switch, and 5 is the series switch for making and breaking the circuit. Thecontroller-drumis providedwith the contact-strips 6, 7,8, 9, and 10, with which the stationary contacts 11, 12, 13, 14, 15, 16, 17, and 18 engage. The first-named six of these stationary contacts are located at one side of the drum and the last-named two at the opposite side, as is clearly indicated in Figs. 1 and 11 of the drawings. The drum is also provided with a lug or projection 19 about midway of its length, the purpose of which will be hereinafter specified.

The controller-drum 2 is rigidly mounted upon a sleeve 20, which surrounds the shaft 21 and is free to turn thereon. Rigidly mounted on the lower end of the sleeve 20 is a notched plate 22, the number and position of the notches in this plate corresponding with the various running positions of the controller. A two-armed lever or pawl 23 is pivotally mounted upon the frame, the lower end of the shaft 24 of the reversing and cut-out therefor in the present instance. The long arm 23 of this lever or pawl is provided at its free end with a roller 23, which engages with the notches in the notched disk 22. The free end of the short arm 23 of the lever or pawl 23 is connected to a lug on the frame or stand 1 by means of a coiled spring 25. The notched holding-plate 22 is provided near one edge with two downwardly-projecting pins or lugs 22, located some distance apart, the purpose of which will be hereinafter specified. Mounted rigidly upon the shaft 21 of the controller-drum, just below the notched plate 22, is a cam-plate 26, provided with an upwardlyprojecting lug or pin 20, which is located fine wire 50.

between the lugs or pins 22 on the notched plate 22 and in such a position as to engage the one or the other, according to the direction in which the shaft is turned. A second cam-plate 27, mounted rigidly upon the shaft of the controller-drum below the cam 26, is provided with seven projecting points or teeth 27, 27 27 27, 27 27 and 27 the first four constituting a group which is separated from the other group of three by spaces of considerable width, one of such spaces being nearly twice as great as the other. The two projecting ends of the cam 26 are located between these two groups of projecting teeth on the cam 27. A rock-shaft 28 is mounted in suitable bearings on the frame 1, and on its upper end is mounted rigidly ahead 29. This head is provided at one end near its upper side with apivoted pawl 30, which is normally pressed outward by means of a coiled spring 31. The outer or free end of the pawl 30 is provided with a roller 32, and its inner end is provided with a shoulder 30, which engages with a corresponding shoulder on the head 29 and is held thereagainst by the coiled spring 31, above referred to. At or near the other end of the head 29 is a projection 33, on which is mounted a roller 33, the latter being in the same horizontal plane with roller 32 and having no movement independently of the head 29 except that of rotation on its axis. A pawl 34, similar to pawl 30, is pivotally mounted upon the head 29 below the projection 33, and its free end is provided with a roller 35, which is normally in vertical alinement with the roller The pawl 34 is also provided at its inner end with a shoulder 34, which engages with a corresponding shoulder on the head 29 and is normally pressed against the same by means of a coiled spring 36. Rigidly mounted upon the rocksh'aft 28 below the head 29 is a plate 37, having a rack or internal segmental gear 38, concentric with said rock-shaft. Meshing with this curved rack is a pinion 39,

which is keyed to the upper end of a rock shaft 40, the latter being mounted in a bearing 41. A bar 42 is rigidly mounted upon the rock-shaft 40 below the bearing 41 and is provided at its ends with spring contact-arms 43. above described have also rigidly connected with them a disk or plate 44, provided with two notches 44 and 44, a holding pawl or lever 45 being pivoted to the frame and pro vided at its free end with a roller 46, which engages with the notches above referred to. The said holding pawl is pressed inward against the plate 44 by means of a coiled spring 47.

Extending from each stationary contact 48 of the switch 5 through nearly a semicircumference is a series of small contact-pins 49. Each of these contact-pins 49 extends down wardl y and is connected to aresistance-coil of These resistance-coils are connected in series and are embedded in insula- The bar 42 and rock-shaft 40 tion 51, which is inclosed in a casing or frame 52, preferably of metal and in the form of a hollow cylinder, provided with bearings 53 for the shaft 40, which carries the movable member of the switch.

The shaft 24 for the reversing and cut-out switch is mounted in suitable bearings on the frame or stand 1, and the drums 3 and 4 are loosely mounted thereon, one above the other, so that each may be rotated independently of the other when desired. The upper drum is provided with suitable contact strips or plates 54, 55, 56, 57, 58, and 59 and the lower with similar plates 54, 55, 56 57, 58, and 59, and cooperating therewith are stationary contacts 60, 61, 62, 63, 64, and 65 and 60, 61, 62, 63, 64, and 65. The stationary cut-out contacts 60, 61, 60, and 61 are located at one side of the drums, and the stationary reversing-contacts 62, 63, 64, 65, 62, 63, 64, and 65 are located at the opposite side. The upper drum is provided at its lower side with a disk 66, having a handle 67 projecting therefrom, and with a pivoted locking-lever 68, having a laterally-projecting inner end 68, which engages with a recess in the shaft 24 when the drum is in position to include the corresponding motor in the circuit. (See Fig. 7.) The disk 66 is also provided with a spring 69 for normally forcing the end 68 into contact with the shaft 24. The upper end of the lower drum is provided with dc vices which are duplicates of those just described. Each disk is provided at one side with a projection 70, having a notch 71, which receives a pin 72 on one end of a pivoted lever 73. The pin 72 is held in contact with the peripheries of the disks 66 by a spring 74. \Vhen the end of the lever 73, carrying the pin 72, is moved outward by the projection 70, its opposite end is moved inward into position to engage the stop 19 on the drum 2, and thus prevent the rotation of the drum beyond the series contacts. Mounted between the controller-drum and the reversing and cut-out drums is a lever 75, which is pivoted at one end to the frame and is pressed toward the reversing and cut-out switch by a coiled spring 76. This lever is provided on the side adjacent the controller-dru m with a lug or projection 75 and on the opposite side with three notches 75 75, and 75. The shaft 24 of the cut-out and reversing switch is provided with an arm 77, in the end of which is mounted a roller 78 in position to engage with the notches in the lever just described. Vhen the reversing switch is in either of its operative positions, the roller 78 will rest either in notch 75 or in notch 75, but when in its inoperative position the roller will be in engagement with the middle notch 75 and the lever 75 will be thrown toward the controller-drum. Mounted upon the upper end of the controller-shaft is a disk 79 in the same horizontal plane with the lever 75, and this disk is provided with a notch 80, which receives the projection 75 on the lever '75 when the controller-drum is in the off position and the shaft of the reversing-switch is in its intermediate position. This interlocking device therefore serves to prevent any movement of the controller-drum except when the reversing-switch is in one or the other of its operative positions, and it also prevents reversing the motors or either of them except when the controller-drum is in its off position.

Assuming that the several parts are in the positions indicated in Figs. 1, 4, and 7 of the drawings, the operation is as follows: The shaft 21 is rotated in the positive directionthat is,.from left to right-by means of a handle. (Not shown.) The cams 26 and 27, being rigid with this shaft, will turn with it until the pin 26 on the cam 26 engages with the rear pin 22 on the notched plate 22. The distance between the pins 26 and 22 is such that there is considerable lost motion between the cam 26 and plate 22, and consequently between the shaft 21 and the drum 2. The engagement of the pin 26 with the pin 22" will cause the rotation of the drum in the direction of movement of the shaft 21; but before the stationary contacts 11, 12, and 13 come into engagement with the contact-plates 6 and 8 on the drum the cam 26 will have moved the rocking head 29 and its shaft 28 into the positions indicated in Fig. 2 by reason of the engagement of said cam with the roller 32 on the end of the pawl 30. By reason of the lost-motion connection between the drum 2 and its shaft 21 and the cooperating action of the notched plate 22 and the springactuated holding-pawl 23 the final movement of the drum at each notch effected quickly and also independently of the movement of the shaft 21,.since the instant that the end of any tooth of plate 22 has passed the roller on the end of arm 23 the spring 25, acting upon the pawl 23, will force the roller inward, and thus move the plate forward independently of the shaft 21. The possibility of arcing between the stationary contacts and the strips on the drum by reason of failure to move the controller-handle quickly to a runningposition is thus avoided. The head 37, being keyed to the shaft 28, will be moved therewith and rotate the shaft 40 by means of the rack 38 and pinion 39, so as to move the contact ends of the arms 43 from the off position over the pins 49 to the stationary'contacts 48, and thus close the circuit. When the head 29 is thus rocked by means of the cam 26, the roller 35 on the end of pawl 34 will be moved into contact with the front face of the tooth 2" on the cam 27, and as the coiled spring which retains the pawl 34 normallyin the position shown in Fig. 4 is only strong enough to move the pawl to that position and retain it when unopposed by any other force the free end of the pawl will be moved inward upon its pivot by the tooth 27, and thus permit the said tooth to pass the pawl and its roller. lVhen the roller on the end of the arm 23 of the holding-pawl 23 has reached the second notch in the plate 22, as indicated in Fig. 2, the pawls 30 and 34 will have assumed their normal positions with reference to the head 29, but the head will be rocked into the position shown in Fig. 2, so that the roller 35 is in the notch between the teeth 27 and 27 of the cam 27 and the roller 32 on pawl 30 is outside of the path of movement of the cam 26. With the operating parts in the position just described the roller 46 on the end of the holding-pawl 45 will be in the notch 44 of the plate 44, as indicated in Fig. 3, and the switch 5 will thus be held in closed position against any accidental movement or shaking of the parts tending to displace the movable contacts. The movement of the controller-shaft in the positive direction another step or until the roller on the end of the arm 23 of the lever 20 is in engagement with the third notch in the plate 22 will effect no movement of the head 29 and of the series switch 5, for the reason that the tooth 27" will merely rock the pawl 34 on its pivot against the action of the spring 36, and the same is true of the subsequent movement of the drum, until the end of the cam 26 opposite to that which first actuated the rocking head 29 reaches the roller 33, and this occurs just before the change from series to parallel connection of the mo tors is to be made. Since the bearing of the roller 33 is not movable with relation to the head 29 and the roller is in the path of movement of the end of cam 26 referred to, it will be understood that a further movement of the cam 26 in the same direction will necessarily force the roller 33 out of its path of movement, and thus rock the shaft 28 and head 29 into the position shown in Fig. 5. The head 37 will be consequently rotated at the same time and in the same direction, and by reason of the rack 38 and pinion 39 the contacts 43 will be moved quickly over the resistance contact-pins 49 to the open-circuit positions and the roller 46 of the arm 45 will rest in the notch 44 in the plate 44. The resistances 50, which are thus progressively cut into circuit by means of the engagement of the contacts 43 with the contact-pins 49, are so proportioned that the current will be gradually reduced until its volume is insufficient to form any injurious are between the moving contacts and the last contact-pins. The resistance-coils are also so proportioned that there will be no arcing between any of the contact-pins and the movable contacts engaging therewith. It will also be understood that this opening of the circuit and cutting in of the resistances is by reason of the gearin g employed effected very quickly, the movement of the contacts 43 being much more rapid than that of the shaft 21. Having thus opened the circuit before the contacts 11 to 16 of the controller proper have left the contact strips or plates 6, 8, and 9, the separation of these parts will obviously be upon open circuit.

. when the motors are connected in parallel, it

When the parts are thus separated, the cams and rocking head will be in the position indicated in Fig. 5. The further movement of the shaft 21 and the connected parts will cause the cam 26 to move the pawl 30 out of its path, and thus rock the pawl 3t into such position that its roller 35 will be in contact with the periphery of the cam 27 in front of tooth 27. The further movement of the controller-handle in the same direction through the various positions of the multiple connection of the motors will have no eifect upon the switch 5 for the reason, as has been already described, that the teeth of the cam 27 will merely rock the pawl 31 inward on its pivot out of their path of movement without moving the head 21). This position of the parts will be maintained until the final notch is reached, their position at the final notch being indicated in Fig. 6. If it is desired to stop the motors by reversing the controllerdrum from any point to which it may have been moved, the lost-motion connection between the plate 22 and the cam 26 will come into play, and consequently the cam 27 will be moved so that its tooth which is adjacent to the roller 35 will engage said roller and rock the head 29 into the position indicated in Figs. 4 and 5, thus opening the switch 5prior to the opening of the circuit upon the controller-dru 111, this operation of the parts being effected by reason of the engagement of the shoulder 34 with the corresponding shoulder on the head 29. The head 29 being once moved into this position a complete reversal of the drum may take place without any movement of the rocking head by reason of the fact that the cam 26 will in impinging against the roller 32 merely rock its pawl out of the way, and thus allow it to pass.

Since the teeth 272.27 27, and 27 on the cam 27 correspond to the several running positions of the controller-drum when the motors are connected in series and the teeth 27 27 and 27 to the several running positions will be noted that the switch 5 will be initially opened by the turning of the drum backward from any running position to the preceding one. It will also be noted that the two actuating projections or teeth of the cam 26 are located between the two sets of teeth on the cam 27, and that consequently when the circuit is opened by any one of the teeth 27, 27 27, and 27 it cannot be again closed except by continuing the reversal of the drum to the zero position or by moving it in the positive direction until the cams are in the position indicated in Fig. 5. It is also apparent that when the motors are connected in parallel and the circuit is opened by means of any one of the teeth 27 27 and 27 it cannot be again closed except by continuing the reverse movement of the drum until the cams are in the position indicated in Fig. 5. It follows,

therefore, that whenever the circuit is opened for the purpose of stopping or reducing the 'tacts 6t and 65 with plate'59.

open.

speed of the motors the latter cannot be again connected in the circuit without at the same time including either all or the greater portion of the starting resistance.

The circuit connections and changes in and through the controller are as follows: Assuming that the combined reversing and cut-out switch and the controller-drum are in the positionsindicated diagrammatically in Fig. 11, it will be understood that the roller 78 on the end of the arm 77 (shown most clearly in Fig.

7) is in the middle notch 75 of the lever 75. When in this position, the lug or pin 75 is in the notch 80 in the disk 70, and there can consequently be no movement of the controller-drum until the shaft 24: and drums 3 and 4 are rotated to bring the roller 78 either into notch 75 or notch 75. As illustrated in Figs. 1 and 7, the last-named position is the one occupied by the said parts. When the reversing-drums are in the position indicated in Figs. 1 and 7, the stationary contacts and 61 will be in engagement with plate 54, contacts 60 and 61 in engagement with plate 54, contacts 62 and 63 in engagement with plate or strip 58, contacts 6st and with plate 59, contacts 62 63 with plate 58 and con- If the controller-drum be then rotated to bring the stationary contacts 17 and 18 into position a and the contacts 11 16 into position h, (indicated in Fig. 11,) the current coming in at the contact 17 will pass from plate or strip 7 tostrip 6, these two being electrically connected, as indicated'in the drawings, thence through the contacts 11, 63, 58, and 62, the field-magnet F of the first motor, contacts 64, 59, and 65,

the armature A of the first motor, stationary contact 13, strip 8, contact 12, contacts 60, 54,

(and 61, contacts 63, 58*, and 62, fieldmag net F of the second motor, contacts 64B 59 :65, the armature A of the second motor, the contacts 60", 54:, and 61, contact 14, resistances R, R, and R contact 16, through the series switch 5.

and out Withc-ut followingthe circuits in detail for the various subsequent positions of the controller-drum it will be seen by reference to Fig. 12 that in the second running position (designated as b) the resistance R is shortcircuited, in position 0 resistances R and R are short-circuited, and in position d all of the resistances are short-circuited, the motors in each of these three positions being in series. In positions 6, f, g, and h the circuit is In position i the motors are in parallel and resistance R is short-circuit-ed. In position j the motors are in parallel and resistances R R are short-circuited, and in position 70, or the final position, the motors are in parallel and all the resistances are short-circuited.

If the reversing-switch drums be rotated so as to bring the roller 78 into the notch 75 and the stationary contacts 62 63, 850., into contact with the corresponding stationary contacts 55 56, &c., the circuits will be the same as above described, exceptthat the current will be reversed through the field-magnets F and F of the motors.

If it is desired to cut out one of the motors from the circuit, it is merely necessary to grasp the arms 67 and the lever 68 on the disk 66, move the lever 68 toward the arm 67, thus withdrawing its end 68 from the notch in the shaft 24, and rotate disk 66 and the corresponding drum until the pin 72 on lever 73 drops into the notch '71 in the disk 66. This will bring the end of the lever 73, adjacent to the drum 2, into such position as to be engaged by the stop 19 when the drum has been rotated through the various positions for the series connection of the motors. In this position of the reversing and cut-out drum the ends of the contact-strip 54: or the strip 5?, as the case may be, will be, respectively, in engagement with the stationary contacts 61 and 63 or 61 and 63, as the case may be, from which it will appear without following out the circuits in detail that the corresponding motor will be cut out of circuit. As the drum thus rotated to cut out the circuit is not locked to the shaft 24, it is obvious that the other drum may be moved by means of said shaft to reverse the motor remaining in circuit, if desired.

WVhile we have illustrated and described specific mechanism for practicing our invention, we desire it to be understood that changes may be made in the details of construction and the arrangement of parts without departing from the spirit and scope of the invention.

Ve claim as our invention- 1. In a controller for electric motors, the combination with a circuit-changing and resistance-varying switch, of a circuit making and breaking switch in series therewith, variable resistances at the terminals of the lastnamed switch so proportioned as to gradually but quickly reduce the current (and at the same time prevent arcing between any of the switch-contacts), and a movement-controlling connection between said switches.

2. In a controller for electric motors, the

combination with a shaft, a contact-bearing drum mounted thereon and stationary contacts cooperating with said drum, of an isolated circuit making and breaking switch, a variable resistance between the terminals of said switch and means intermediate said shaft and said switch for actuating the latter in advance of the movement of the drum.

3. In a controller for electric motors, the combination with a circuit making and breaking switch and operating-gearing therefor, of a controller drum, an actuatingshaft on which said drum is loosely mounted, a cam rigidly mounted upon the lower end of said shaft and engaging said switch operating gearing, a notched plate rigid with said drum and a lost-motion connection between said notched plate and the cam carried by the actuating-shaft.

4. The combination with a circuit making and breaking switch, having a'variable resistance between its terminals, an oscillatory head geared to the movable member of said switch, and a rotatable shaft provided with meansfor engaging and moving said head, of a controller-drum loosely mounted upon said rotatable shaft and having a lost-motion connection therewith.

5. In a controller for electric motors, the combination with a circuit-changing and resistance-varying switch and a circuit making and breaking switch in series therewith, of a reversing-switch and interlocking means between the latter and the first-named switch whereby the motor or motors can be reversed only when the first-named switch is in its olf position.

6. In a controller for electric motors, the combination with a shaft provided with two cam-plates, of a drum loosely mounted upon said shaft and provided with a notched disk or plate, a lost-motion connection between said disk or plate and one of said cam-plates, a spring-actuated holding-pawl cooperating with the notched disk or plate, a circuit making and breaking switch, and operating mechanism therefor actuated by the cam-plates on the controller-shaft.

'7. In a controller for electric motors, the combination with a circuit making and breaking switch, a rocking head and gearing connecting said head with the movable member of the switch, of a drum, an actuating-shaft therefor and means carried by said shaft for moving said rocking head.

8. In a controller for electric motors, a circuit making and breaking switch the movable member of which is provided with a pinion, in combination with a rock-shaft, a segmental gear and a head on said rock-shaft, adrum, an actuating-shaft for said drum and means carried by said shaft for moving the head carried by the rock-shaft.

9. In a controller for electric motors, a switch-actuating rocking head provided with two pivoted pawls in different horizontal planes and with a projection in the same horizontal plane with one of said pawls in combination with a rotary shaft provided with cams cooperating with said projection and pawls to move said rocking head.

' 10. In a controller for electric motors, the combination with stationary contacts, a cooperating contact-bearing drum and an actuating device having a lost-motion connection therewith, of a circuit making and breaking switch and opening and closing mechanism therefor actuated or controlled by a backward movement of the drum-actuating device from any point to open said switch and by a forward movement to close the same only when the drum is in position to include the neces sary current-reducing resistance in circuit.

11. In a series-parallel controller for electric motors, the combination with stationary contacts, a cooperating contact-bearing drum, and an actuating device having a lost-motion connection therewith, of a circuit making and In testimony whereof We have hereunto sub- 10 breaking switch and opening and closing scribed our names this 26th day of October, mechanism therefor actuated to open said A. D. 1896.

switch by the backward movement of the drum-actuating device from any point and to close the same only when the drum is either in the zero position or between the positions Witnesses:

corresponding to series and parallel connec- WESLEY G. CARR,

tion of the motors. HUBERT C. TENER. 

